For all its expressions of confidence, the Obama administration has been unable to implement key elements of the law, including the employer mandate and its associated reporting requirements. By delaying those for a year, the president has set off a cascade of implementation problems — making verification of eligibility for subsidies more difficult (and so proposing to give away billions in benefits on the honor system next year) and confirmation of compliance with the individual mandate impossible.

Meanwhile, assurances about the quality of the state exchanges have fallen by the wayside. ("Let's just make sure it's not a third-world experience," one administration official told a health industry gathering this spring.) And the promise that things won't change for those who now have insurance is being abandoned. ("Depending on the plan you choose in the marketplace, you may be able to keep your current doctor," an HHS website assures visitors.) Perhaps most ominously, as state premium costs for 2014 trickle out, it seems likely they will be too expensive to attract the large numbers of young and healthy people the system requires in order to function.

But there are a few bold, determined public officials who may rescue Obamacare. Among them are Sens. Ted Cruz, R-Texas, Marco Rubio, R-Fla., and Mike Lee, R-Utah. This is not, of course, their intention. They hate the law but have chosen to fight it in a particularly counterproductive way, which discredits responsible opposition and makes a Democratic takeover of the House more likely.

Cruz and crew have proposed to cut off funding for the government unless President Obama agrees to defund the Affordable Care Act. This big idea is supported by a few conservative advocacy groups (Club for Growth, Heritage Action for America) and has gained talk-radio momentum. Cruz views this as the last stand against Obamacare — a conservative Alamo or Thermopylae. Instead, it would be a Little Bighorn. Cruz bids to become a Custer for our time.

The outcome is predetermined by the choice of the battlefield. Any legislative effort to defund Obama's central domestic achievement would provoke a presidential veto, requiring two-thirds of the Senate and House to override. This goal has a Dewey Decimal System problem: It is located not in political science but in science fiction.

An actual shutdown of the government — the only realistic outcome of Cruz's strategy — works for conservatives only if voters generally blame it on Obama's intransigence. So: Americans would need to side with a distrusted faction of a disdained institution, which is pursuing a budgetary maneuver that even many Republican lawmakers regard as aggressive, desperate and doomed. "This is misleading the conservative base," says Sen. Tom Coburn, R-Okla., "because it's not achievable." Sen. Richard Burr, R-N.C., has called it the "dumbest idea" he has ever heard.

If I were prone to conspiracy theories, I'd suspect a false flag operation. Since I'm not, there must be explanations that arise from within tea party ideology.

First, it seems to involve a rigid form of economic determinism. Cruz argues: "Jan. 1 is when the exchanges start and subsidies start. ... It is an iron rule of politics that those who receive subsidies, inevitably, after they start receiving those subsidies, fight to retain those subsidies." This "iron rule" is Mitt Romney's 47 percent comment unbound — the government-dependence theory of politics. When the subsidies start flowing, it is all over, even if the system itself is a dysfunctional mess. This is a critique of the American people more than of Obamacare. Once again, it is hard to persuade voters you regard as potential benefit addicts.

Second, tea party ideology also involves a counterproductive disdain for the Republican Party. "Let me be clear," Cruz famously said, "I don't trust the Republicans." Other tea party activists spin third-party fantasies. But the Republican Party is the only institution capable of reversing Obamacare. Here is an actual iron rule: A measure passed by a Democratic president, House and Senate (and approved by the Supreme Court) can be reversed only by a Republican president, House and Senate. And the picking of lopsided, losing fights makes this prospect less likely.

Third, these strategic considerations make no difference to those who regard strategy itself as evidence of compromise. In this view, the hopeless battles are the most purifying. This is the romance of Cruz and of Custer — but both are myths that end in pointless defeat.